Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/77—Preparation of chelates of aldehydes or ketones
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
  • C07C49/92—Ketonic chelates

Definitions

• the present invention relates to an alkaline earth metal salt of a ⁇ -diketo compound which is used as an auxiliary for resin molding, and to a method for producing the same.
• Alkaline earth metal salts of ⁇ -diketo compounds (hereinafter, referred to as ⁇ -diketo compound salts or salts of ⁇ -diketo compounds) are utilized as auxiliaries for resin molding, particularly, as nonpoisonous or nontoxic stabilizers for vinyl chloride resin molding.
• ⁇ -diketo compound salt Various methods for producing the ⁇ -diketo compound salt are known.
• Zh. Neorg. Khim. (1990), 35(11), 2776-80 discloses a method for producing a ⁇ -diketo compound salt by a reaction between acetylacetone and calcium chloride or calcium nitrate.
• the method is disadvantageous in terms of quality, because it is necessary to remove impurities such as a chloride and a nitrate (or a nitric acid salt) contaminating the resulting ⁇ -diketo compound salt (acetylacetonato).
• JP-B-60-24777 describes a method for producing a ⁇ -diketo compound salt by adding an alkaline earth metal hydroxide to a ⁇ -diketo compound (e.g., acetylacetone) in a ratio of 1 mol of the former to the equivalent (2 mol) of the latter.
• a ⁇ -diketo compound e.g., acetylacetone
• the ⁇ -diketo compound salt thus obtained is not suitable for use as a stabilizer, because the salt contains about 6 to 7 % by weight of moisture (corresponding to one molecule of water of crystallization).
• the salt contains about 6 to 7 % by weight of moisture (corresponding to one molecule of water of crystallization).
• the salt contains about 6 to 7 % by weight of moisture (corresponding to one molecule of water of crystallization).
• the stability of the ⁇ -diketo compound salt produced in accordance with the process of the literature is low, the salt cannot be preserved for long periods of time.
• German Patent DE96-19610320 describes a method for producing a ⁇ -diketo compound salt by adding a ⁇ -diketo compound (e.g., acetylacetone) to an alkaline earth methyl hydroxide in the absence of a solvent using 1 mol of the latter and the equivalent (2 mols) of the former.
• a ⁇ -diketo compound e.g., acetylacetone
• the ⁇ -diketo compound is added to the alkaline earth metal hydroxide and reacted at 40°C or lower, thus preventing the viscosity of the reaction mixture from becoming too high and making it possible to react the reaction mixture in the form of particles or powder.
• the ⁇ -diketo compound needs to be added slowly in order to prevent the viscosity from becoming too high. Therefore, it takes time to complete the reaction, the conversion is low (for example, about 94 % when hydrated lime is used), and the resulting ⁇ -diketo compound salt is of lower purity.
• the inventors of the present invention have found that, when an alkaline earth metal hydroxide such as calcium hydroxide remains unreacted, the purity of a ⁇ -diketo compound salt is remarkably decreased during its preservation probably because of the condensation of an acetylacetone unit of the ⁇ -diketo compound salt. Based on such knowledge, the inventors did intensive research to achieve the above objects, and finally found that, when an aliphatic ⁇ -diketo compound is used in an excess amount relative to the amount of an alkaline earth metal compound, the resulting ⁇ -diketo compound salt is of high purity and highly stable. The present invention was accomplished based on the above findings.
• the present invention is a method for producing an alkaline earth metal salt of a ⁇ -diketo compound from a powdery alkaline earth metal compound and an aliphatic ⁇ -diketo compound, wherein 2.04 mol or more of the aliphatic ⁇ -diketo compound is used relative to 1 mol of the alkaline earth metal compound.
• the reaction may be carried out while supplying the alkaline earth metal compound and the aliphatic ⁇ -diketo compound continuously or intermittently, or by adding one component to the other continuously or intermittently.
• the total amount of each component used need only be within the above range, and the amount of each component in a reaction stage or a supply stage need not be within the above range.
• the highest temperature throughout the reaction may be 50 °C or higher, and a drying operation may be conducted at 100 to 180 °C in an atmosphere of an inert gas.
• the alkaline earth metal compound may be calcium hydroxide, magnesium hydroxide, or barium hydroxide.
• the aliphatic ⁇ -diketo compound may be represented by the following formula (1): wherein R 1 and R 2 are same or different, each representing hydrogen atom, a C 1-6 alkyl group, or a C 1-10 alkoxy group, or may be an acetoacetic acid C 1-4 alkyl ester or acetylacetone.
• the alkaline earth metal salt of the ⁇ -diketo compound of the present invention is produced according to the method as described above.
• the alkaline earth metal salt of a ⁇ -diketo compound contains 1% by weight or less of water (moisture) and has a purity of not less than 98 % by weight.
• alkaline earth metal compound there may be exemplified hydroxides of alkaline earth metals (for example, magnesium hydroxide, calcium hydroxide, and barium hydroxide). These alkaline earth metal compounds may be used singly or as a combination of two or more species.
• alkaline earth metals for example, magnesium hydroxide, calcium hydroxide, and barium hydroxide.
• the alkaline earth metal compound may be used in the form of particles or in powdery form. Those commercially available for industrial use may be used as they are.
• the mean particle size of the alkaline earth metal compound is about 0.1 to 300 ⁇ m, preferably about 0.1 to 150 ⁇ m.
• the alkaline earth metal compound contains little or no impurities (e.g., silica, alumina, alkaline earth metal carbonates).
• the amount of impurities is, for example, 2% by weight or less, preferably 1 % by weight or less, more preferably 0.5 % by weight or less.
• R 1 and R 2 may be same or different, each representing hydrogen atom, a C 1-6 alkyl group (for example, C 1-4 alkyl groups such as methyl and ethyl groups), or a C 1-10 alkoxy group (for example, C 1-6 alkoxy groups such as methoxy, ethoxy, propoxy and butoxy groups).
• C 1-6 alkyl group for example, C 1-4 alkyl groups such as methyl and ethyl groups
• C 1-10 alkoxy group for example, C 1-6 alkoxy groups such as methoxy, ethoxy, propoxy and butoxy groups.
• Preferred aliphatic ⁇ -diketo compounds are compounds represented by the formula (1) wherein R 1 is a C 1-4 alkyl group (e.g., methyl group, ethyl group) and R 2 is a C 1-4 alkyl group (e.g., methyl group, ethyl group) or C 1-6 alkoxy group (e.g., methoxy, ethoxy, propoxy and butoxy groups). Even when both R 1 and R 2 are C 1-4 alkyl groups, they may be the same or different C 1-4 alkyl groups.
• acetylacetone and acetoacetic acid C 1-4 alkyl esters e.g., methyl acetoacetate, ethyl acetoacetate.
• the aliphatic ⁇ -diketo compound is used in an amount of not less than 2.04 mol, for example, about 2.04 to 5 mol (for example, about 2.05 to 4.5 mol), preferably about 2.1 to 4 mol (for example, about 2.1 to 3 mol), more preferably about 2.2 to 2.8 mol (for example, about 2.2 to 2.6 mol), relative to 1 mol of the alkaline earth metal compound.
• the amount of the remaining alkaline earth metal compound is reduced by merely using the aliphatic ⁇ -diketo compound in an amount slightly exceeding 2 mol.
• the viscosity of the reaction mixture becomes high (i.e., like a viscous paste) at near the end of the reaction, and therefore it is difficult to stir the mixture.
• salts of ⁇ -diketo compounds can be produced by reacting the ⁇ -diketo compound with the alkaline earth metal compound while maintaining the flowability of the powder (or particles).
• the reaction between the alkaline earth metal compound and the ⁇ -diketo compound can be carried out by supplying the alkaline earth metal compound and the ⁇ -diketo compound to a reactor continuously or intermittently.
• the reaction between the alkaline earth metal compound and the ⁇ -diketo compound can be performed by supplying these compounds to a reactor capable of mixing (apparatuses for kneading or blending powders, such as kneaders, channel-type dryers, ribbon blenders) via a feeder or supplying machine (e.g., metering supply machine).
• each component When continuously or intermittently supplying the alkaline earth metal compound and the aliphatic ⁇ -diketo compound to the reactor, each component may be supplied to the reactor in the aforementioned proportion, or each component may be supplied such that the proportion of the component at the end of the supply (the total of each component used) is within the range mentioned above.
• the reaction may be effected by adding, between the alkaline earth metal compound and the aliphatic ⁇ -diketo compound, one component to the other.
• the reaction mixture may sometimes grow viscous in the latter half of the reaction. Accordingly, it is advantageous to carry out the reaction by adding the aliphatic ⁇ -diketo compound to the alkaline earth metal compound continuously or intermittently.
• the method has the advantage of maintaining the mixture in a powdery state throughout the whole procedure, i.e., from the reaction step to the drying step.
• a method which comprises steps of charging a reactor capable of mixing (e.g., apparatuses for kneading or blending powders, such as kneaders, channel-type dryers, ribbon blenders) with the particles or powder of alkaline earth metal hydroxide, and then adding the ⁇ -diketo compound continuously or intermittently while stirring the particles or powder.
• a reactor capable of mixing e.g., apparatuses for kneading or blending powders, such as kneaders, channel-type dryers, ribbon blenders
• the proportion of each component at the end of the reaction (the total amount of each component used) need only be within the range set forth.
• the reaction is usually performed while controlling the reaction temperature by removing the reaction heat by means of cooling (e.g., jacket cooling).
• the reaction temperature is, for example, about 0 to 100 °C, preferably about 30 to 100 °C, more preferably about 60 to 80 °C.
• a reaction temperature exceeding 100°C causes the loss of the aliphatic ⁇ -diketo compound, leading to a consequent reduction in the conversion of the alkaline earth metal compound.
• the quality of the resulting ⁇ -diketo compound salt (color, purity, stability, etc.) is deteriorated.
• the highest temperature during the reaction is kept at 50 °C or higher (for example, about 50 to 100 °C), 55 °C or higher (for example, about 55 to 95 °C, particularly about 55 to 80 °C).
• the highest temperature in the reaction is 50 °C or higher, since the conversion rate of the alkaline earth metal compound is raised, the resulting salt of the ⁇ -diketo compound is improved in terms of purity and stability.
• the reaction may be is carried out in a batch system, a semibatch system or a continuous system.
• the reaction mixture obtained batchwise or semi-batchwise may be subjected to an aging if necessary. Aging of the reaction mixture further increases the conversion rate of the alkaline earth metal compound.
• the temperature for aging is, about 40 to 100 °C, preferably about 50 to 90 °C, more preferably 60 to 80 °C. When the temperature for aging exceeds 100 °C, the quality of the resulting ⁇ -diketo compound salt (e.g., color, purity, stability) is deteriorated due to the loss of the aliphatic ⁇ -diketo compound.
• the aging time may suitably be selected.
• the aging time is usually 1 hour or longer, preferably about 1 to 24 hours (for example, 1 to 16 hours), more preferably about 4 to 12 hours. Alternatively, the time may be about 2 to 8 hours.
• the reaction mixture usually contains water of crystallization and water generated during the reaction [for example, 2 mol of by-product water is generated when 1 mol of hydrated lime is used]. Accordingly, the salt of the ⁇ -diketo compound is obtained by drying the reaction mixture, directly after the reaction or after completion of the aging, for removing the by-produced water or the water of crystallization.
• the drying may be carried out in an atmosphere of an inert gas (for example, nitrogen, helium, carbon dioxide), preferably under a flow (or a stream) of an inert gas (for example, while blowing an inert gas to a reactor).
• an inert gas for example, nitrogen, helium, carbon dioxide
• a flow (or a stream) of an inert gas for example, while blowing an inert gas to a reactor.
• the product is colored due to the oxidation or condensation of the ⁇ -diketo compound. If necessary, the drying operation is performed under reduced pressure.
• the drying temperature (when drying while elevating the temperature, this term refers to the finally reached temperature) is usually about 100 to 180 °C, preferably about 100 to 150 °C (for example, about 120 to 150 °C).
• the drying temperature can be selected according to the species of the ⁇ -diketo compound salt. As to the representative ⁇ -diketo compound salts, their preferable drying temperatures are shown in Table 1.
• Compound Preferable drying temperature Decomposition temperature Calcium acetylacetonate 130 to 160 °C 269 °C Magnesium acetylacetonate 110 to 120 °C 160 °C Barium acetylacetonate 120 to 140 °C 243 °C Calcium ethyl acetoacetate 120 to 140 °C 221 °C Calcium methyl acetoacetate 120 to 140 °C 229 °C Magnesium ethyl acetoacetate 120 to 140 °C 247 °C Magnesium methyl acetoacetate 120 to 140 °C 255 °C
• An excess of the ⁇ -diketo compound can be removed by drying.
• the removed ⁇ -diketo compound can be condensed and trapped (or collected) together with the by-produced water using a condenser or the like, and the trapped ⁇ -diketo compound is reusable for reactions using other portions of alkaline earth metal compound.
• the drying may be performed either in the reactor mentioned above, or in a batch system, a semibatch system or a continuous system.
• the powdery alkaline earth metal compound and the ⁇ -diketo compound are continuously supplied and dried.
• the use of an excessive amount of the ⁇ -diketo compound relative to the amount of the alkaline earth metal compound and continuous supply of the components make it possible, with industrial advantages, to produce ⁇ -diketo compound salts within a short period of time without lowering the quality, and therefore the method of the present invention is economically advantageous. If necessary, the aging operation may be performed.
• the aliphatic ⁇ -diketo compound is continuously or intermittently added to the powdery alkaline earth metal compound, for providing a ⁇ -diketo compound salt of high quality, it is preferred that 2.1 to 3 mol of the ⁇ -diketo compound relative to 1 mol of the alkaline earth metal compound is used; the aging is performed if necessary; and that the resulting salt is dried at 100 to 150 °C in an atmosphere of an inert gas.
• the salt of ⁇ -diketo compound thus obtained is of high purity, and the purity of which is usually 98.0 % by weight or more.
• the water (moisture) content of the salt is 1 % by weight or less, preferably 0.8 % by weight or less, more preferably 0.5 % by weight or less, and usually about 0.1 to 0.8 % by weight (particularly, about 0.1 to 0.5 % by weight).
• the amount of impurities is 2 % by weight or less, preferably 1.8 % by weight or less, more preferably 1.5 % by weight or less, and usually about 0.1 to 1.8 % by weight (particularly, about 0.1 to 1.5 % by weight). Since the content of impurities is low, the ⁇ -diketo compound salt of the present invention is highly stable.
• the alkaline earth metal content of the ⁇ -diketo compound salt is reduced, highly stable ⁇ -diketo compound salts of high quality are consequently provided.
• ⁇ -diketo compound salts of high purity can industrially advantageously be produced at high conversions.
• ⁇ -diketo compound salts of high quality can be produced within a short period of time by reacting an alkaline earth metal compound with a ⁇ -diketo compound while supplying them continuously, and therefore the method of the present invention is economically advantageous.
• the ⁇ -diketo compound salt of the present invention can be utilized as a stabilizer for vinyl chloride resins.
• the salt is available for use as a low-effervescent stabilizer.
• the ⁇ -diketo compound salt can stably be used over long periods of time due to its high stability.
• the product was subjected to the drying step, and dried at 68 to 73 °C for 24 hours until the product attained a moisture content of 6.8 % by weight.
• the dried product was cooled to give 1,550 g of yellowish white calcium acetylacetonate [yield 99.1 mol% (calcium hydroxide basis), purity 91.5 % by weight].
• the whole product (1683 g) resulted from the reaction was transferred to a rotary evaporator, and dried while ventilating with a nitrogen gas (5 L/hr) at 80 °C for 36 hours under reduced pressure (30 Torr).
• the moisture content of the product decreased to 6.3 - 6.4 % by weight in 24 hours after the drying operation has started, but little or no change was observed since then.
• the product was cooled to give 1,540 g of acetylacetone calcium [yield 98.7 mol% (calcium hydroxide basis), moisture 6.3 % by weight, purity 91.7 % by weight].
• the product was subjected to the drying step, and dried at 106 to 138 °C for 10 hours until the moisture or water content was reduced to 0.46 % by weight. Thereafter, the dried product was cooled to give 1,425 g of white calcium acetylacetonate [yield 98.2 mol% (calcium hydroxide basis), purity 98.6 % by weight].
• the product When the temperature was elevated up to 65 °C, the product was subjected to the drying step, and dried at 104 to 125°C for 12 hours until the product attained a moisture content of 0.17 % by weight. The dried product was cooled to give 1,342 g of white magnesium acetylacetonate [yield 99.3 mol% (magnesium hydroxide basis), purity 98.9 % by weight].
• a distillate resulted from the drying was two-layered. 232 g of Acetylacetone containing 5.3 % by weight of water was collected from the upper layer.
• the product was subjected to the drying step, and dried at 110 to 122 °C for 18 hours until the product attained a moisture content of 0.65 % by weight. Thereafter, the dried product was cooled to give 1,618 g of white calcium methyl acetoacetate [yield 97.9 mol% (calcium hydroxide basis), purity 98.1 % by weight].
• the product When the temperature was elevated up to 66°C, the product was subjected to the drying step, and dried at 106 to 125 °C for 12 hours until the product attained a moisture content of 0.44 % by weight. Thereafter, the dried product was cooled to give 1,435 g of white calcium acetylacetonate [yield 98.5 mol% (calcium hydroxide basis), purity 98.2 % by weight].
• a distillate resulted from the drying was two-layered. 111g of acetylacetone containing 5.1 % by weight of water was collected from the upper layer.
• NES-KO-KNEADER continuous mixing machine for powders
• the upper layer contained 94.9 % by weight of acetylacetone and 4.6 % by weight of water (or moisture).
• the upper layer contained 94.5 % by weight of acetylacetone and 5.2 % by weight of water (or moisture).
• Example 1 Each calcium acetylacetonate obtained in Example 1, 5, 6, or Comparative Example 1, 2, 3 or 4 was sealed within a container, and kept at a temperature of 25 ⁇ 1 °C under a humidity of 75 ⁇ 2 % for examining the stability of the salt.
• the stability was evaluated from changes in the purity of the acetylacetone as the time went by (from the time of sealing to after 12 months). The results are shown in Table 2.
• the distillate contained 62.8 % by weight of methyl acetoacetate and 36.6 % by weight of water (or moisture).

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• 1998
  • 1998-07-10 JP JP10196247A patent/JP2000026362A/ja active Pending
• 1999
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